for Veterans and the Public

The thymus is a gland that is involved in the regulation of the body's immune response. Thymus extract supplements are made from the thymus glands of cows or calves and are sold as capsules and tablets. Although thymus extract products often carry claims of boosting the immune system to fight diseases such as hepatitis C, few studies have been performed, and there is little evidence to show that they work.

Taking thymus extract does not seem to carry many risks. Because the extracts come from animals, however, there is the possibility of contamination from diseased animal parts. For this reason, people with suppressed immune systems, such as people with HIV/AIDS or those who have had organ transplants, should be careful taking these products.